Abstract:To study the dynamics of Pinus massoniana population of the secondary forest, a sample plot (240 m×240 m) was set on Laoshan island of Qiandao Lake Region. All trees were tagged and measured to analyze the population structure and spatial distribution patterns. The individuals at 1st and 2nd age size were few, accounted for 0.06% and 1.01% of total, respectively. The juvenile individuals were severely lacking. The individuals at 5th age size were the dominant, and accounted for 28.28% of total. The spindle type population structure and convex curve survivorship suggested the population was stable with a declining trend. But the population would not be withdrawn from the community in a short time because there were a large number of medium size class individuals. The negative mortality of the small size classes indicated the seedlings were severely deficient and the population tended to decline in a long time. The spatial distribution pattern of total individuals or individuals at different size classes of P.massoniana presented clumping distribution. Aggregation index of the population was declining from saplings, medium size trees to mature trees. Totally, the population would diffuse in trend.